I have 2 questions:
Just had oil changed. Now when going up hill at about 40 mph car sounds like muffler is missing. Otherwise sounds fine
After cold night at first start I put key in ignition. Right when I turn the key is hear a sound that sounds like several gears grinding at one time. But car starts right up.
The sound mimic the same noises when I tried driving a stick shift and I didn’t engage the correct gear.
Since this is essentially a brand new car take it back to the dealer. They might have, somehow, damaged something during the oil change.
I tested the new CR-V for a week and my test vehicle didn’t do either of these things. Well worth a dealer visit and may be get some cell phone sound recordings if you have a passenger that can help.
Have you checked the oil level to verify they actually filled it back up after the change?